Self-cleaning high lift bucket



July 13, 1954 A. BAKER 2,683,542 SELF-CLEANING HIGH LIFT BUCKET Original Filed Feb. 27, 1951 3 Sheets-Sheet l IINVENTOR.

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SELF-CLEANING HIGH LIFT BUCKET Original Filed Feb. 27,1951 3 Sheets-Sheet s nwmrox. l/frea' Baker.

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Patented July 13, 1954 UNITED STATES PATENT OFFICE SELF-CLEANING HIGH LIFT BUCKET Alfred Baker, Washington, Pa.

9 Claims.

This invention relates generally to excavating machines and more particularly to improvements in the high lift excavator.

This application is a continuation of my application Serial No. 212,90l. filed February 27, 1951, and 275,989, filed March 11, 1952, both now abandoned. The disclosures of these previously filed applications have been combined with no new matter to form the disclosure of this application.

When excavating a gummy clay commonly called gumbo, it is very difiicult, if not impossible, to clean the high lift bucket of the clay when digging and loading vehicles. It is substantially impossible to work continuously as the operator is required to leave his control position in the high lift and use a shovel or crowbar or other suitable means for digging out the high lift bucket in order to permit him to dig with some efilciency, otherwise the partly filled high lift bucket will not permit him to dig and load the trucks as readily as he could in dry dirt or shale.

The object of this invention is the provision of a scraper arm for use at the high lift bucket for the purpose of scraping the bucket as it is tipped to empty the same.

Another object of this invention is the pro vision of means for automatically or selectively permitting the scraper arm to remain inoperative. When handling, digging stone or heavy shale it is best not to move the scraper arm as the boulders or other heavy rock will fall of their own accord and. the bucket does not need to be scraped at this time. If the scraper arm is forced to operate when stone is in the high lift bucket, the weight of the stone is apt to break the chain or other member of the scraper device. This improvement is also directed to an interlocking means for placing a scraper arm in or out of service at the selection of the operator.

Another object of this invention is the provision of means for automatically operating the scraper arm. The scraper arm is biased to scrape the bucket when dumped, and if the load is too heavy, it will not move. When handling or digging stone or heavy shale, the scraper arm pushes against such boulders or other heavy rock, and if their weight is too great, the arm will. not move.

Another object of this invention is the provision for automatically scraping a high lift bucket while dumping the same.

Another object is the provision of a pressure biased scraping blade for the bucket of an earth moving device which operates to scrape the material out of a tilting bucket unless the weight of the material is greater than a predetermined amount. The ultimate pressure to resist operation of the scraper blade may be determined by the size and strength of a spring. If the bucket is handling clay, the spring is usually made suificiently strong to overcome the scraping resistance. If the bucket has a heavy rock or stone it is usually not necessary to scrape the bucket while clumping and the spring does not have sufiicient force to shove under the stone and as the bucket tilts, the spring merely stretches further until the stone falls out and the blade then moves around the bucket without encountering resistance.

One or more springs may be employed, but the preferred structure employs two springs, one connected to each dumping arm at each side of the bucket. The other ends of the springs are connected to scraper actuating levers that are geared to the scraper blade so that if the bucket is tilted and the scraper blade is against a heavy object so that it cannot move relative to the bucket, then the lever does not move and the springs are expanded. Thus, if the resistance to movement of the scraper blade is relatively small, then the lever stretches the springs only that amount necessary to hold the blade against this resistance while the bucket is tilted, thus causing the latter to be scraped.

The sprockets and chains may be replaced by levers or crank arms connected together by pitmen. However, the chain connection provides the safety link in the system and will break due to excessive working pressures, thus preventing the more expensive parts from being destroyed.

When the bucket is tilted back to its normal or loading position, the levers are provided with stops that strike the tilting arms and the scraper blade returns to the top of the bucket and the pressure is released from the springs.

The term crank means is employed herein to define the structure of the sprockets and their connecting chains which may be replaced by gears or crank arms connected by chains or cables.

Other objects and advantages appear hereinafter in the following description and claims.

The accompanying drawings show, for the purpose of exemplification without limiting the invention or the claims thereto, certain practical embodiments of the invention wherein:

Fig. l is a side elevation of a high lift indicating the several positions of the bucket.

Fig. 2 is the top plan view of the bucket as shown in Fig. 1.

Fig. 3 is a detailed side elevation of the high lift bucket with a chain plate removed to show the operating chain of the scraper arm.

Fig. 4 is a sectional view taken on the line l- 3 of Fig. 2 showing the high lift bucket with its attachment to the dumping arms.

Fig. 5 is a sectional view taken along the line 55 of Fig. 2. v

Fig. 6 is a sectional view taken along the line 6-9 of either Fig. 2 or Fig. 4. a

Fig. '7 is a sectional view of a modification showing a resilient latch.

Fig. 8 is a sectional view of the modification similar to that of Fig. 6.

Fig. 9 is a detailed view of the resilient latch and lever.

The high lift excavating machine as. illustrated on the drawings comprises the mobile power unit or tractor l which has pivoted thereto a pair of lifting arms 2 and a pair of dumping arms 3. The lifting arms 2 are pivoted at 4 to the frame on the tractor and are actuated by the pivotally mounted fluid-operated cylinders 5 which extend and retract their pistons: 6 that are pivoted at their. outer ends 7 to the plates 8- on the underside. ofthe lifting arms 2. As shown in Fig. 1

the lifting arms 2 supporting the bucket 10 are illustrated in their extreme positions, the lower position being a position when the bucket IE] is resting. onthe ground and the upper position pivotally mounted cylinders M, each of which has apiston pivotall-y secured to. its respective plate l2 as indicated at IS. The dumping arms 3 may assume the same. position with respect to the lifting arms 2 when the bucket i is: on the ground or whenthe bucket it is in the air and as illustrated at IT. However when the cylinders 14 are energized to move.- the plates [2 and their dumping arms 3 outwardly, the bucket H! is in the position as indicated in dot and dash lines at [8.

The bucket it is pivoted at 26 to the ends of the lifting arms. The; pivots are carried by the dual pair of. plates 2 l on the underside of the bucket. Two other pairs of ears or plates are provided at 22 for receiving the shafts 23 which pivotally secure the dumping arms 3. relative to the bucket It. as: shown in Figs. 4 and 6. The shafts 23 may be: made'into one single. long shaft but the short stub shafts. work satisfactorily.

Each of the shafts 23: is. journaled in its respective dumping arm. 3 and the plates 22,. and also in the bearings 2'4 in rearwardly projecting housings 25 on the back of the bucket it. The outer end. of each shzuzt 23 has a sprocket gear I!) secured thereto and is: retained within each housing 25-. Shaft 23 is provided. with the clutch member 26 which is splinedi or otherwise keyed to. the shaft 23 as indicated. at. 21?. The clutch member 26. has a plate 285 welded thereto, which plate is provided with an outwardly open slot 28 as shown in- Fig; 4- arrangedto receive the looking. latch or detent as which is pivotally secured to the dumping arm as indicated atv 31' in Fig. 2. A servomotor 32 is fastened on the dumping arm 3 and is provided with a piston 33 which is pivotally attached to the latch 38. for the purpose of inserting and retracting the. same in the slot 29. The servomotor 3.2 may be a fluid-operated cylinder or a solenoid or it may be actuated manually. Nevertheless the servomotor is preferably controlled from the operators seat in. the vehicle or tractor i. When the piston 33' is retracted the latch 39 is withdrawn from the slot 29 in the plate 28 and, since the shaft 23 idles in the 4 bearings 24 and the plates 22 and the dumping arm 3, the shaft is free to rotate relative to these members when the latch is withdrawn. However, when the latch 30 is inserted in the slot 29, the shaft 23 becomes locked relative to the dumping arm 3.

As shown. in Fig. 3 the outer end of each of the shafts 23' has the sprocket gear i9 secured thereto. The high lift bucket H3 is provided with an arcuate rear wall, as indicated at 35, so that it may have the scraper blade 36 with its beveled cutting edges 3'! operate from the upper position, as indicated in Fig. 4, to the lower position as indicated at it in Fig. l. The scraper blade is secured to. the ends of, the radial arms 33 that are. fixedly attached to the stub shafts 46 in the center of the arc The shafts extend through the wall of the bucket H3 and have secured thereto the sprocket gear 4| as indicated in Figs. 3 and 5. The sprocket gear it has twenty teeth and the gear 19 has thirty teeth. Thusthe sprocket gear 4! has two-thirds of the number of teeth as the sprocket gear I9 and since they are connected by the chain. 42, the sprocket gear it will be rotated with its shaft 43 when the bucket i0. is moved relative to the pivot point 26 by the dumping arm 3. In view of the fact that the sprocket gear id is fixed relatively to the dumping arm, the bucket is revolved about the pivot point 20, the chain 42 in effect passes around the sprocket l9 which provides motion to the small sprocket t! and causes the scraper blade to'travelfrom the position as indicated at 53- to. l in Fig- 1, when the bucket I0 is tipped from the position as indicated at H to the position asinclicated at 18.

When the servomotor 32 is energized to with draw the; latch than-:1 unlock the plate 28 relative to the dumping arm 3, the scraper blade 38- will remain at the top of the bucket, as illustrated in Fig. 4, as its friction will not permit it to move in any way even though the bucket is manipulated for the full extent. The plate 28 and the shaft 23 will remain in the same relativeposition to the bucket is as illustrated in Fig. 4., until the dumping, arm is brought to the lowermost position, as illustrated in full lines in Fig. l and in Fig. l, so astov permit the latch 36' to be slid back in the slot for locking the shaft 23 relative to the dumping. arm 3. Thus by simple manipulation of a control of the servomotor 32 one may invoke the use of the scraper blade 35 for the purpose of scraping the bucket when it is operating in sticky clay and when operating in stones the scraper blade may be released and permitted to stay at the top of the bucket where it Will not be harmed.

A guide plate 55' may be placed within the enclosure of the sprocket gears 59 and m for the purpose of taking up the slack in the chain and in order to make the walking action of the chain around the sprocket l9 eifective in rotating the sprocket gear 5!. If it is desirable to remove the chain, the guide :25 may be removed which materially loosens the chain in its flight. A cover i6 is provided to enclose the sprockets 53- and 4! to prevent dirt from entering therein. Thus the chain and sprockets may operate in oil or grease which can seep through the bearings past the shafts 16 and 23 and thereby lubricate the arms 38 within the bucket and also lubricate the bearing 24.

As shown in Fig. 2 the high lifts employ a dual pair of lifting arms and a dual pair of dumping arms and require-two spaced pivotal pointswhich support the bucket It on the end of the arms. Only one side of the high lift has been described, however, the opposite side is exactly the same and is operated in unison therewith. It is far better to provide a driving means on both sides of the high lift bucket H) to dump the same.

In the modification shown in Figs. 7, 8 and 9 illustrating the automatically operated scraper arm, the clutch members 26 are replaced by the right and left hand lever members s1 and 43 which are splined or otherwise keyed to the shafts 23 as indicated at 21. The outer ends of the levers are connected by the rod G9 so that they will operate in unison. A stop 50 in the form of a projection is welded to the side of each of the arms 41 and 48 and is arranged to strike its respective plate 5| welded to the dumping arms 3. As the dumping arms 3 pull the bucket back to the positions shown in Figs. 1 and 7 the stops 50 engage the plates 5| and prevent further pivoting in this direction. The rod 49 has a spring 52 attached at each end thereof adjacent the levers $7 and 8. The other ends of these springs are fastened to a bracket 55 on its respective dumping arm 3. Upon fastening the springs 52 to the rod d9 they are subjected to the greatest movement. Holes 53 are provided in the levers 41 and 48 for shortening the movement of the spring.

The shaft 23 is free to rotate relative to the bucket and the dumping arms 3, but being secured to the levers 41 and A3 is limited in its movement when the stops 50 strike the plates 5! In view of the fact that the sprocket gear 34- is fixed relatively to the dumping levers t7 and 48, the chain 42 in effect passes around the sprocket 34 which provides motion to the small sprocket A! and causes the scraper blade to travel from the position as indicated at 43 into M in Fig. 1, when the bucket i9 is tipped from the position as indicated at H to the position as indicated at 8. The stub shaft 49 is also journaled in the bearing carried by the plate 46.

When the resistance to movement of the scraper blade is greater than the tension on the springs 52, the levers move with the bucket and the springs expand. The scraper blade 35 will remain against the obstruction in the bucket until this resistance to movement is removed, then the stretched springs retract the levers Ill and 48 to swing the scraper through its arc. Thus, the scraper blade 38 functions automatically for the purpose of scraping the bucket when it is operating in sticky clay, and when operat ing in stones the resistance to movement of the scraper blade may even keep it at the top of the bucket until the resistance is removed.

I claim:

1. A high lift excavator comprising, a mobile power unit, lift arm means operatively carried by said power unit and pivotally attached to a bucket to raise the same, a dump arm means operatively carried by said power unit and pivotally attached to said bucket in spaced relation to the pivotal attachment of the lift arm means to tilt said bucket forwardly on the pivot of the lift arm means to empty the same, a pivoted member on said bucket and having a dirt scraper attached thereto, and intermediate drive means connecting said pivoted member to the dump arm means to multiply the rotation of the scraper making it travel through a greater are than the rotation of the bucket as the latter is tipped forwardly by the dump arm means to empty the same.

2. The structure of claim 1 characterized in that said bucket has a circular arcuate portion and said scraper comprises a U-shaped member having its ends journaled on each side of said bucket to scrape the circular arcuate portion.

3. The structure of claim 1 characterized in that said pivoted member is a sprocket and the intermediate drive means includes a sprocket chain and a second sprocket with a connecting means to hold the second sprocket relative to the dump arm means and produce relative movement between the bucket and the scraper when the bucket is dumped.

4. The structure of claim 1 characterized in that said pivoted member and said last-mentioned intermediate drive means include sprockets which are connected by a chain to multiply the rotary action of the scraper.

5. The structure of claim 4 characterized in that one of said sprockets is releasably connected to the dump arm means and is journaled on the dumping arm pivot and is selectively locked relative to said dump arm means and when unlocked permits the scraper to remain at rest relative to the bucket when the bucket is tipped.

6. The structure of claim 4 characterized in that one of said sprockets is journaled on the dumping arm pivot and is connected through a resilient means to said dump arm means to permit the scraper to remain at rest relative to the bucket when the resistance to movement of the blade is greater than the fiexure of the resilient means when the bucket is tipped.

7. The structure of claim 1 characterized in that said intermediate drive means includes a sprocket attached to said pivoted member, a chain around said sprocket, and resilient means connecting said sprocket and said dump arm means to rotate the scraper and scrape the bucket as the dumping arm means tips the bucket forwardly on the pivot of the lift arm means to dump the same.

8. A high lift excavator comprising, a mobile power unit, lift arm means operatively carried by said power unit and pivotally attached to a bucket to raise the same, a dump arm means operatively carried by said power unit and pivotally attached to said bucket in spaced relation to the pivotal attachment of the lift arm means to tilt said bucket forwardly on the pivot of the lift arm means to empty the same, a pivoted member on said bucket and having a dirt scraper attached thereto, crank means attached to said pivoted member, and intermediate rotary drive means connected through the pivot between the bucket and said dump arm means to drive said crank means and multiply the rotation of the scraper making it travel through a greater are than the rotation of the bucket to scrape the bucket as the dumping arm means tips the bucket forwardly on the pivot of the lift arm means to dump the same.

9. The structure of claim 8 characterized in that said intermediate rotary drive means is releasably locked relative to said dumping arm means.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,246,527 Bentson Nov. 13, 1917 1,729,744 Knauer Oct. 1, 1929 2,472,758 Przybylski June 7, 1949 2,482,612 Drott et a1 Sept. 20, 1949 2,491,793 Andersen Dec. 20, 1949 

